The present invention relates generally to production of articles of manufacture that are sensitive to ESD (electro static discharge) such as IC (integrated circuit) packages, and more particularly, to a method and system for automatically monitoring the amount of ESD (electro static discharge) from each of a plurality of operators in a production area to minimize damage to the articles of manufacture caused by ESD (electro static discharge) from the plurality of operators.
Referring to FIG. 1, an IC (integrated circuit) package 10 is an example article of manufacture that may be damaged during production by ESD (electro static discharge) from an operator. The IC package 10 includes a housing 12 for carrying an IC (integrated circuit) die 14 therein, as known to one of ordinary skill in the art of IC package manufacture. The IC package 10 also includes a plurality of leads 22, 24, 26, 28, and 30 for providing connection to nodes of the integrated circuit fabricated on the IC die 14, as known to one of ordinary skill in the art of IC package manufacture. A typical IC package has more numerous leads, but five leads 22, 24, 26, 28, and 30 are shown in FIG. 1 for clarity of illustration.
During production of IC packages, operators handle such IC packages in a production area for manufacture of the IC packages. An operator when in the production area for manufacture of IC packages typically wears specially made footwear that is amenable for dissipating charge from the operator to the ground for minimizing electro static charge accumulation on the operator. However, an unacceptable level of electro static charge may accumulate on the operator. When such an operator touches an IC package, an unacceptable level of ESD (electro static discharge) may be passed to the IC die of the IC package resulting in permanent damage to the IC die of the IC package.
Thus, referring to FIG. 2, an operator 50 is instructed to measure the amount of ESD (electro static discharge) from the operator 50 before entering a production area at the start of a work shift. The operator 50 measures the amount of ESD (electro static discharge) from the body of the operator 50 at an ESD (electro static discharge) measuring unit 52. The operator 50 stands on a charge dissipating mat 54 that is coupled to a ground node of the ESD measuring unit 52. The charge dissipating mat 54 is typically comprised of a conductive material, and footwear 56 of the operator 50 makes contact with the charge dissipating mat 54. The operator 50 then places a hand 58 to a measuring node of the ESD measuring unit 52.
In this manner, the ESD measuring unit 52 determines a resistance of the operator 50 from the hand 58 to the footwear 56 of the operator 50. Such resistance correlates to the ESD (electro static discharge) from the body of the operator 50. An example of such an ESD measuring unit 52 that is available to one of ordinary skill in the art of IC package manufacture has the model number of SP-30110-SPI from SPI (Static Prevention Incorporated) located in Brea, Calif.
In the prior art, each of a plurality of operators assigned to work during a predetermined work shift is instructed to measure the ESD (electro static discharge) from the body of the operator and to manually record the result on a chart toward the start of the predetermined work shift. In the prior art, a production supervisor examines the chart toward the start of the predetermined work shift to identify any operator having an unacceptable level of ESD (electro static discharge). In addition, in the prior art, another employee gathers the daily charts for the prior month to manually create a monthly report that summarizes the ESD (electro static discharge) measured for each of the operators. The production supervisor examines the monthly report to identify any operator consistently having an unacceptable level of ESD (electro static discharge) for the prior month such that such an operator may be advised to replace his/her footwear.
However, in the prior art, some of the operators forget or fail to measure the ESD (electro static discharge) on a daily basis. Thus, unacceptable levels of ESD (electro static discharge) from some operators are not detected resulting in damage to the IC dies during production of IC packages. In addition, time and labor is wasted when the employee gathers the daily charts for the prior month to manually create the monthly report in the prior art. Furthermore, some daily charts are misplaced resulting in incomplete monthly reports of the ESD (electro static discharge) measured for each of the operators.
Thus, a mechanism is desired for automatically monitoring that each of a plurality of operators in a production area measures the ESD (electro static discharge) and for automatically recording the ESD (electro static discharge) measured from each of the plurality of operators. With such complete measuring and recording of the ESD (electro static discharge) from each of the plurality of operators, reports generated from such data may be used to effectively minimize damage to the articles of manufacture caused by ESD (electro static discharge) from the plurality of operators.
Accordingly, in a general aspect of the present invention, a computer system is used for monitoring that each of a plurality of operators assigned to work during a predetermined work shift has checked into the production area and has measured the ESD (electro static discharge) at an ESD (electro static discharge) measuring unit.
In a general aspect of the present invention, a first identification reader reads a respective badge identification of each operator who checks into the production area. A computer system has a data storage unit for storing the respective badge identification of each operator who checks into the production area in a first working file. An ESD (electro static discharge) measuring unit measures an amount of ESD (electro static discharge) from the body of an operator, and a second identification reader reads a respective badge identification of each operator who measures a respective amount of ESD (electro static discharge) from the body of the operator at the ESD (electro static discharge) measuring unit. The respective badge identification and the respective amount of ESD measured for each operator who measures the respective amount of ESD at the ESD measuring unit are stored in a second working file of the data storage unit of the computer system.
A database stores data regarding a plurality of operators working in the production area, and the computer system includes a data processor for generating a list of operators assigned to work during a predetermined work shift from data stored in the database, at a start of the predetermined work shift. The data processor of the computer system assigns a respective flag to each operator in the list of operators assigned to work during the predetermined work shift, at the start of the predetermined work shift, by processing data from the first working file and the second working file stored in the data storage unit of the computer system.
In addition, the data processor assigns a first flag to an operator if a respective badge identification of the operator is recorded in the first working file indicating that the operator has checked into the production area, and if the respective badge identification of the operator is recorded in the second working file indicating that the operator has measured a respective amount of ESD (electro static discharge) from the body of the operator at an ESD (electro static discharge) measuring unit. The data processor assigns a second flag to an operator if a respective badge identification of the operator is not recorded in the first working file indicating that the operator has not checked into the production area, and if the respective badge identification of the operator is recorded in the second working file indicating that the operator has measured a respective amount of ESD (electro static discharge) from the body of the operator at an ESD (electro static discharge) measuring unit. Furthermore, the data processor assigns a third flag to an operator if a respective badge identification of the operator is recorded in the first working file indicating that the operator has checked into the production area, and if the respective badge identification of the operator is not recorded in the second working file indicating that the operator has not measured a respective amount of ESD (electro static discharge) from the body of the operator at an ESD (electro static discharge) measuring unit. Finally, the data processor assigns a fourth flag to an operator if a respective badge identification of the operator is not recorded in the first working file indicating that the operator has not checked into the production area, and if the respective badge identification of the operator is not recorded in the second working file indicating that the operator has not measured a respective amount of ESD (electro static discharge) from the body of the operator at an ESD (electro static discharge) measuring unit.
In another embodiment of the present invention, the respective flag assigned to each operator with the predetermined work shift and a date of the predetermined work shift is stored in the database. A daily report is generated, at one of a plurality of computer systems networked in the production area and coupled to the database, with the respective flag assigned to each operator for the list of operators, at the start of the predetermined work shift. Furthermore, a monthly report is generated, at one of the plurality of computer systems networked in the production area and coupled to the database, with the respective flag assigned to each operator for the list of operators, for each date of the predetermined work shift during a prior month, from data stored in the database.
In this manner, the daily report readily identifies any operator who has failed to measure the ESD (electro static discharge) such that the production supervisor may further instruct such an operator to measure the ESD (electro static discharge). The monthly report readily identifies any operator who consistently has an unacceptable level of ESD (electro static discharge) for the prior month such that the production supervisor may instruct such an operator to replace his/her footwear. Thus, damage may effectively be minimized to the articles of manufacture caused by ESD (electro static discharge) from the plurality of operators.
These and other features and advantages of the present invention will be better understood by considering the following detailed description of the invention which is presented with the attached drawings.